Field
Embodiments described herein relate to quantum dots. More particularly, embodiments relate to quantum dots in quantum dot LED displays.
Background Information
State of the art displays for phones, tablets, computers and televisions utilize glass substrates with thin-film transistors (TFTs) to control transmission of backlight through pixels based on liquid crystals. More recently emissive displays such as those based on organic light emitting diodes (OLED) have been introduced because they can have a faster response time, and be more power efficient, allowing each pixel to be turned off completely when displaying black or dark colors. Even more recently, quantum dot light emitting diodes (QD-LEDs) have been introduced as an alternative display technology, potentially being more power efficient than OLEDs.
Quantum dots are semiconductor materials where the size of the structure is small enough (e.g. less than tens of nanometers) that the electrical and optical characteristics differ from the bulk properties due to quantum confinement effects. For example, the emission properties of quantum dots are related to their size and shape in addition to their composition. When an electric field is applied to a QD-LED electrons and holes move into the quantum dot layer where the electrons and holes are captured in the quantum dots and recombine, emitting photos. The emission wavelength can be tuned by changing the size of the quantum dots. Typically, smaller quantum dots emit bluer light (higher energy) and larger quantum dots emit redder light (lower energy).